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fix: touch throttle #81

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Merged
abelonogov-ld merged 8 commits into from
Nov 14, 2025
Merged

fix: touch throttle #81

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d19b225
update throttling
abelonogov-ld Nov 13, 2025
ea7c82a
Updated throttling constants
abelonogov-ld Nov 13, 2025
fb73ef4
Adjusting touch points forming
abelonogov-ld Nov 13, 2025
59244e7
Fix startPoint
abelonogov-ld Nov 13, 2025
830c0e0
back to start point
abelonogov-ld Nov 13, 2025
ee313e0
remove print
abelonogov-ld Nov 13, 2025
0cc123d
Update
abelonogov-ld Nov 13, 2025
7c767b7
fix updating track
abelonogov-ld Nov 13, 2025
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54 changes: 35 additions & 19 deletions Sources/LaunchDarklyObservability/UIInteractions/TouchIntepreter.swift
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Original file line number Diff line number Diff line change
@@ -1,9 +1,10 @@
import UIKit

private enum TouchConstants {
static let tapMaxDistance = 12.0
static let tapMaxDistance = 4.0
static let tapMaxDistanceSquared: CGFloat = tapMaxDistance * tapMaxDistance
static let touchMoveMaxDuration: TimeInterval = 0.11
static let touchMoveThrottle: TimeInterval = 0.05 // From RRWeb code
static let touchPathDuration: TimeInterval = 0.18 // found through testing
}

final class TouchIntepreter {
Expand Down Expand Up @@ -47,26 +48,41 @@ final class TouchIntepreter {
track.end = touchSample.timestamp
track.target = touchSample.target

let trackDuration = track.end - track.start
guard trackDuration <= TouchConstants.touchPathDuration else {
// flush movements of long touch path do not have dead time in the replay player
let lastPoint = TouchPoint(position: touchSample.location, timestamp: touchSample.timestamp + uptimeDifference)
track.points.append(lastPoint)

let moveInteraction = TouchInteraction(id: incrementingId,
kind: .touchPath(points: track.points),
startTimestamp: track.start + uptimeDifference,
timestamp: touchSample.timestamp + uptimeDifference,
target: touchSample.target)
track.points.removeAll()
track.start = lastPoint.timestamp - uptimeDifference
track.startPoint = touchSample.location
tracks[touchSample.id] = track
yield(moveInteraction)
return
}

let previousTimestamp = (track.points.last?.timestamp ?? track.start)
let duration = touchSample.timestamp + uptimeDifference - previousTimestamp
guard duration >= TouchConstants.touchMoveMaxDuration else {
guard duration >= TouchConstants.touchMoveThrottle else {
return
}
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@cursor cursor bot Nov 13, 2025

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Bug: Inconsistent Throttle Timing Post-Flush

After flushing touch points when track duration exceeds touchPathDuration, the throttle check is skipped for subsequent points because track.points is empty. The previous implementation used track.start as a fallback timestamp when no points existed, ensuring consistent throttling. Without this fallback, points immediately following a flush bypass time-based throttling and rely only on distance checks, potentially capturing points more frequently than touchMoveThrottle allows.

Fix in Cursor Fix in Web

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@abelonogov-ld abelonogov-ld Nov 13, 2025

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I want that more frequently


let distance = squaredDistance(from: track.startPoint, to: touchSample.location)
guard distance >= TouchConstants.tapMaxDistanceSquared else {
return
if let lastPoint = tracks[touchSample.id]?.points.last {
let distance = squaredDistance(from: lastPoint.position, to: touchSample.location)
guard distance >= TouchConstants.tapMaxDistanceSquared else {
return
}
}

track.points.append(TouchPoint(position: touchSample.location, timestamp: touchSample.timestamp + uptimeDifference))
tracks[touchSample.id] = track

let trackDuration = track.end - track.start
if trackDuration > 0.9 {
// flush movements of long touch path do not have dead time in the replay player
flushMovements(touchSample: touchSample, uptimeDifference: uptimeDifference, startTimestamp: track.start, yield: yield)
}

case .ended, .cancelled:
// touchUp
let startTimestamp = tracks[touchSample.id]?.start ?? touchSample.timestamp
Expand Down Expand Up @@ -97,13 +113,13 @@ final class TouchIntepreter {
startTimestamp: startTimestamp + uptimeDifference,
timestamp: touchSample.timestamp + uptimeDifference,
target: touchSample.target)
track.points.removeAll()
tracks[touchSample.id] = track
yield(moveInteraction)
}

func flushTrack(touchSample: TouchSample, uptimeDifference: TimeInterval, yield: TouchInteractionYield) {

if let lastPoint = track.points.last {
print("touchPath.points: \(track.points.count)", touchSample.id)
track.points.removeAll()
track.start = lastPoint.timestamp - uptimeDifference
tracks[touchSample.id] = track
yield(moveInteraction)
}
}

func squaredDistance(from: CGPoint, to: CGPoint) -> CGFloat {
Expand Down
34 changes: 17 additions & 17 deletions TestApp/Sources/AppDelegate.swift
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,27 +6,27 @@ import LaunchDarklySessionReplay
//let mobileKey = "mob-a211d8b4-9f80-4170-ba05-0120566a7bd7" // Andrey Sessions stg production


let mobileKey = "mob-d6e200b8-4a13-4c47-8ceb-7eb1f1705070" // Spree demo app Alexis Perflet config = { () -> LDConfig in
let config = { () -> LDConfig in
var config = LDConfig(
mobileKey: mobileKey,
autoEnvAttributes: .enabled
)
config.plugins = [
Observability(options: .init(
serviceName: "alexis-perf",
otlpEndpoint: "https://otel.observability.ld-stg.launchdarkly.com:4318",
backendUrl: "https://pub.observability.ld-stg.launchdarkly.com/",

//let mobileKey = "mob-f2aca03d-4a84-4b9d-bc35-db20cbb4ca0a" // iOS Session Production
//let mobileKey = "mob-d6e200b8-4a13-4c47-8ceb-7eb1f1705070" // Spree demo app Alexis Perflet config = { () -> LDConfig in
//let config = { () -> LDConfig in
// var config = LDConfig(
// mobileKey: mobileKey,
// autoEnvAttributes: .enabled
// )
// mobileKey: mobileKey,
// autoEnvAttributes: .enabled
// )
// config.plugins = [
// Observability(options: .init(
// serviceName: "i-os-sessions",
// serviceName: "alexis-perf",
// otlpEndpoint: "https://otel.observability.ld-stg.launchdarkly.com:4318",
// backendUrl: "https://pub.observability.ld-stg.launchdarkly.com/",

let mobileKey = "mob-f2aca03d-4a84-4b9d-bc35-db20cbb4ca0a" // iOS Session Production
let config = { () -> LDConfig in
var config = LDConfig(
mobileKey: mobileKey,
autoEnvAttributes: .enabled
)
config.plugins = [
Observability(options: .init(
serviceName: "i-os-sessions",

sessionBackgroundTimeout: 3,
autoInstrumentation: [.memory, .urlSession])),
Expand Down
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